Needle-actuating mechanism for kntting-machines.



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H. WESTL NEEDLE AOTU ATING MECHANISM FOR KNITTINGMAOHIEES.

APPLICATION FILED JAN 4, 1912. I

Patented Nov. 26, 1912.

5 SHEETS-SHEET 1.

a cane/19a H. H. WEST.

NEEDLE ACTUATING MECHANISM POP. KNITTING MAGHINES.

APPLICATION FILED JANML, 1912.

1 Patented Nov. 26, 1912.

5 SHEETSSHEET 2.

' B Suva 1 km N N W31 fi ljff% Waj attoznup H. H. WEST. NEEDLE AGTUATING MEGHANISMIOR KNITTING MACHINES.

APPLICATION IILBDJANA, 1912. 7

1,045,651 Patented N0v.26, 1912.

'5 SHEETS-SHEET 3.

J 22 fl- @Vitweoc? H. H. WEST NEEDLE ACTUATING MEGHANISM FOR KMPilNfi MACHINES.

APPLICATION FI ED JAN. 4, 1912.

1 UQ5,65L Patented Nov. 26, 1912.

5 bHEEIS-SHEET 4.

% amount-oz wi wwoqeo H; H. WEST. NEEDLE AOTUATING MECHANISM FOR KNITTING MAGHINEQ.

APPLICATION FILED JAN.4, 1912.

15 65 1 a Patented 150126, 1912.

5 SHEETSSHEET 5.

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i H. WEST, 'OF PLYMOUTH, PENNSYLVANIA.

NEEDLE ACTUATING MECHANISM FOR KNITTING-'MACHINES.

t .tleiSAiIii Specification of Letters Patent. Patented NrngQ fi, 19312.

Applicat on filed January 4, 19f? Serial No. 669,395.

To all whom it may concern:

Be it known that I, HARRY H. :VVEST, a citizen of the United States, residingat- Plymouth, in the county of Luzerne. .and

. State of Pennsylvania, have invented certain new and useful improvements in Needle- Actuatiiig Mechai'i'isin ft'or Knitting Machines; and I do declare the following to be a full, clear, and exact description ot-the in vcntion, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in circular knitting machines such as are em tion of the knitting cams on the cam cylinployed in knitting seamless stockings and half hose and. relates especially to needle actuating appliances for producing various designs of knit fabric composed of longitudinal rows of regular meshes separatedby similar rows of tuck stitch meshes, the leg and foot being shown formed of two threads or yarns to produce what is known as plated work.

For convenience in illustration, the invention is shown applied to what is known to the trade as the Banner machine the general structure of which is shown in U. S.

Patent 9333-13 to J. D. Hemphill, dated Sept. 7. 1909, although obviously, the essential features of the invention areapplicab e to other machines of similar characterby the proper modifications in details of construction of the appliances to cause them to cooperate properly with the mechanism of the machines to which they are applied. The machine shown in the patent above referre l to is of the class known as the full automatic machine, in which the knit-t-ing is performed by a circular series of needles which are moved up and down in vertical grooves in the needle cylinder under the acder, which encircles the needle cylinder,t he knitting of the tubular portion of the work forming the leg and foot being performed in continuous circular courses by all the needles under a continuous rotary motion of the needle cylinder inthe direction of the single headed arrow of Figs. 2 and 3 and the pouch knitting or fashioning for the formation of the heel and toe being performed in arc shaped courses by part of the needles under the reciprocatory motion of the needle cylinder, as indicated by the double headed arrow of said figures. Such parts only of the ma chine as. may be necessary to show the concylinder,

ment applied; Fig. 7 is an enlarged detail plan view ofthe cam attachment showing iiection of the draw stitch cam attachmentare illustrated herein. The requisite changes in operation. of the knitting instrumentalities are produced by controlling cams on a 1 change cam shaft which is advanced intermittently at the proper times and by suit able mechanism controls the driving mechanism and needle operating instrumentalit-ies in the .niachine effecting the changes in movement of the knitting cams from"cir-- cular to reciprocatory knitting and the rcverse at the proper times, and also the changes in the knitting cams and special needle operating devices concerned in the narrowing and widening opcrationsat the proper times, and causing the machine to be automatically stopped, or disconnected from the driving power when a stocking is completed.

. One olqect of the invention is to provide an improved needle bitor jack and-a r ad- I justable draw cam for cooperation therewith, adapted to be thrown out of operation for producing different patterns. 1

Another object of the invention is to provide automatically operatedineans for conbeing omitted for convenience in illustra-' tion; Fig. 2 is a horizontal section taken substantially on the line 2-2 of Fig. 1; Fig. 3 is a similar view taken on the line 3-3 of Fig. 1;-'Fig. 4 is agertical transverse section through one side of the needle cylinder and its connected parts, showing this improvedrain and its actuating mechanism in side elevation and in position for engagement with the butts of all the needles; Fig. 5 1s a similar view of a portion of the cylinder with the cam shown in retracted inoperative position; Fig. 6 is a front elevation of a portion of the needleshowing this improved cam attach the cam in position for engagement with the butts of all the needles, a portion ofthe needle cylinder being shown in'herizontal section; Fig. 8 is a similar view with the .cam in position to engage thelong butt.

needles only; Fig. 9 is' a similar view with the cam in retracted position out of the path of the butts of all the needles; Fig. 10 isa similar view with the cam in retracted position and the parts ready to throw the cam into operation at the will of the operator; .Fig. 11 is a longitudinal vertical section taken on the line 1111 of Fig.- 7; Fig. 12 is a transverse vertical section taken on the line 12-12 of-Fig. 7 Fig. 13 represents side elevations respectively of the short and long butt needles employed in a machine of this character; Fig. 14. 1s an en-,

larged detail front elevation'of a portion of the cam ring showing an opening provided with a closure to perinitthe insertion and removal of the needle actuating jacks; Fig. 15 is a vertical section taken on the line 1515 of Fig. 14;; Fig. 16.is a detail perspective view of 'a' portion of the operating mechanism for the adjustable needle pulling down cam, herein termed the draw cam; Fig. 17 is a diagram of tlie'inside .of the cam cylinder showing the needles in position for'forming the draw stitch fabric shown in Fig. 19; Fig. 18 is a similar View showing the needles in position for forming the tuck stitch fabric shown in Fig. 20; Fig. 19 is an enlarged fragmentary view of the fabric formed by the cooperation of the jacks andadjustable pulling down cam shown in Fig. 17; Fig. 20 is a similar view of the fabric formed when the jacks only are employed when the pulling down cam is in inoperative position.

The drawings show the main instrumentalities of a knitting machine to which the present invention may be applied, as comits peripheral or barrel portion with uni-' -derstood that these butts may be formed. near the lower end if desired. These neeprisinga tubular rotary needle cylinder N having a h orizontal beveled gear a secured to its lower end, with which a driving gear (not shown) is adapted to mesh. The

mechanism for driving said gear a is clearly shown in Figs. 3 and 4' of the patent above referred to. j The cylinder N is provided in mechanisms for different purposes. Needles of this class each havea hook a at the upper end thereof, and as shown the lat eral projections or butts are formed at the lower end of the needle, but it is to be undles are also provided attheir outer ends with latches 1%". About one half of the total number of the needles have long butts weasel as a, and the remainder have short butts at". These needles are held in the grooves of the cylinder by the usual spring bands j. This cylinder N is supported in a fiattable or bed plate a), rigidly secured to the top of the machine frame. This bed plate a also supports the several cams and other devices arranged to cooperate with the'needles for automatically throwing the latter into and out of action at predetermined in-- A non 'revoluble but vertically movable cam plate H is bored to reiieivethe revoluble needle cylinder and is'located above and contiguous to said gear a, and. carries the main knitting or needle operating cams and carrying picks which are brought into action durin the knitting of the stocking. A non-revolu le annular needle supporting cam M practically surrounds the lower part of the neetlle cylinder and is secured to and vertically movable with said cam plate H, and is adaptedto support the inactive needles at the normal lower'level while circular knitting is being produced. To the top of the cylinder N is secured an inner ring member 0 having radial grooves alternating with said needle' supporting grooves formed in the cylinder N. The outer edge of the ring projects above but does not extend laterally beyond the bottom of said cylinder grooves. A laterally extending sinker ring a encircles the upper outer part of and extends a short distance above the cylinder barrel and is provided with radial grooves which register with those of the ring'o and in which are seated and supported .the thin horizontally movable sinkers 0. The function of these sinkers'is in. general substantially the same as that of sinkers usually employed. The sinker carrying ring portion of the revolublecylinder is surmountedby arecessed stationary cap ring G, the latter beingsupported by said sinker ring.

The means shown for effecting the comparatively short vertical movement of the cam plate H and the'devlces carried by'it, comprise a cam wheel 9 secured to one endof the cam {shaft .9 and having a cam g on one face thereof, with which a pin g on an arm 9 is adapted to cooperate. This arm 9 is secured to a vertical bar 9 connected with the cam plate H. This cam plate operating device is shown and described clearly in the patent above referred to, and further description thereof is not tervals during the rotation of the cylinder.

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here deemed'necessary. From said patent it will be obvious that this cam plate H and the several devices carried by it are dropped 1 to lowest posit-ion, together with the needles, at predetermined periods when the last knitted stocking is to be run off or stripped from the needles. v

A ca W eel 1 is fixed. to the cam shaft 8 periphery with a plurality of cams Z, j',

the toe of finger 2 of a lever this bell crank is connected'by to turn therewith, and is provided on its with which 3 is adapted to cooperate for a purpose to be described.- This lever 3 is fulcruined intermediately of its ends to the machine frame and the end opposite the toe 2 is connected by a pitnian 4 to one arm of a bell crank 5 fUlClUl'llQCl on a stud 6 which extends laterally from the frame of the machine. The other arm of a link 6 which is mounted to slide Z. having recesses h, z, and c,

witha band 7, longit'ud'nally on of the bed plate at, as is shown clearly in Figs. 1, 2, and 3, the band as shown being provided with slots 8 which engage headed studs 9 projecting laterally from the curved edge of'the bed plate, and which form stops forv limiting the movement of said band in opposite directions. A step-shaped cam lug 1 10 is fixed to said band 7 at a'suitable point scribed. As shown-,-

for cooperation with the draw stitch cam actuating lever to be described. 1

A draw-stitch cam 11 is mountedon the cam ring H at one side of the needle; cylinder, and is adjustable toward and away from thereto, and is adapted to be held in its adjusted. position by suitable means to be dethis cam is secured to one end of a rod 12, which is. slidably and rotatably mounted in the free ends of a' dle and are adapted to shaped bracket 13 to turning. rod 12 substantially U-shaped bracket 13, secured at one end to'the cam plate H and projecting laterally therefrom, as is ,shown clearly in Figs. 4 and 5. A slide14' is mounted on the rod 12, and as shown comprises a bar having.-laterally extending apertured ends 15 and 16, through which the rod 12 passes; F iXed to said rod between the ends of said slide is an adjustable member 17 held in position by a set screw18 and having a pin 19 depending therefrom with its free end projecting into a longitudinally disposed the crossbar of the U- hold said rod 12 against A coiled spring 21. encircles said between the outer end 15 of the'slide 14 and said member 17, and the tension of slot 20 formed in I said spring may be varied by moving said member 17 toward or away from the outer end of the slide 14. A gravity pawl 22 is ivo-tally mounted on the outer end of the rod 12 outside the bracket 13, and is provided on its inner face with laterally projectingspaced stops 23 and 24 which stradengage the opposite sides of the outer leg of the bracket 13 for limiting the pivotal movement of said pawl in opposite directions. The stop 24 is cut out at the inner edge of its free end to form a catch 25- for engaging the outer face .of the upright end of the bracket 13 to lock the pawl in retracted position against the and the curved peripheral edge tion the cam plane at. right angles,

l tension of the spring 21, as is shown clearly in Fig. 10. Z crumed to the "inner end of the bracket 13, as is shown clearly in Figs, 4 and 5 and one arm thereof is pivotally and. ,slidably con nected with the inner .end of'the slide 14, said a'rm having a longitudinal slot 27 therein, which is slidably engaged with a headed stud 28-projecting laterally from said slide 14. The free end of the other arm of said bell crank 26 is resiliently connected with a notch. or step 10 said bell cra-nk'lever arm is designedto ride when the cam is moved under or away from said lever, as will be more fully described hereinafter. i

, It will be obvious that the slot27 in the arm of thebell crank 26 which engages the headed stud 28 will permit said bell crank to swing up and down into the position shown in Figs. 4 and 5, the spring 30 tendto hold it yieldably in engagement with the cam 10 when said cam is positioned thereunder, thereby preventing accidental disengagement of the bell crank from said cam when the machine is in operation.

Between the cain ring M and the cam plate H at the inner face thereof is formed a cam track31 in which the lateral studs or lugs 32 of needle jacks or bits 33- are designed to travel, as shown clearly in Figs. 4, 5, 17 and 18.. This cam track 31 is arranged in the same horizontal plane throughout the greater portion of its length being upwardly deflected as shown at 34 in Figs. 17 and 18 to be described. 'This defor a purpose 34 is preferably of inverted flected portion an obtuse angle and-in which the lugs 32 of the needle jacks 33 travel and are guided. These jacks 32, any desired number of which anay be employed, are slidably mounted in the needle grooves of the cylinder N below as will be hereinafter more fully described. These acks with the draw cam a bracket 29 on the bed plate a by means The step cam 10 secured to the band 7 has ing to draw said bell crank downward and V-shape'as shown, the sides thereof forming.

the needles and are operable by the deflected. portion 34 of the cam track for setting the needles in proper position to take the yarn,

are especially adapted to coact 11, shown in Fig. 17,- as

A bell crank lever 26 is fulvided with'an inclined face 10 on"which -35 and 36 are also arranged for pulling will be presently described. The buttsof the, needles are supportedand guided on the upper edge of the cam ring M, and the usual knit-ting camsin az, e e ,'are employed for raising and lowering the needles 01?, as is clearly described and shown in the Hemphill Patent 933,443, above described. Cams down all the needles which have been elevated by the jacks passing through the elevated portion 34 of the cam track 31, as will.

- be more fully described hereinafter.

' The jacks 33 above referred to for setting the needles, consist merely of small metal slides which are shownv clearly in Figs. 4 and 5., of such-size and form as to fit in the needle grooves'of the cylinder below the ends of the needles, and as above described, are provided wit-h lateral lugs or studs 32 which travel in the cam track 31. The lower ends of these jacks are preferably out away at their lower inner ends and curved to.

adapt them to move-downwardly when the cam ring H is'dropped, without engagement with the needle cylinder, and fit snugly in the space between the outer face ofthe cylinder aid the inner face of the cam ringH, as is shown clearly at 33 in Figs. 4 and 5, the outer face of the cylinder bein curved at this point, also. The needles and Jacks are free to slide in the grooves independently of each other except when the upper ends of thejacks strike against the inner ends of the needles when said jacksride upward in the elevated portion 34of the cam track, as is shown clearly in Figs. 17 and 18. In the drawings, a jack is shown disposed in every other needle groove, but it is to be understood that they may be varied and placed as desired, according to the pattern of the fabric which it is desired to knit. Two yarn feedingdevices 37 and 38 of ordinary or any desired construction are herein shown for feeding two threads to themachine for knitting the tubular fabric for the leg and foot, the feeder 38 being herein designated as the black yarn feeder, and the feeder 37 as the white yarn feeder, for convenience in de scription.

r In the diagram shown in Fig. 17 ,.the draw cam 11 is used in connection with the jacks '33 for forming the well known draw stitchelevated portion 34 of the camtrack which is beneath theyarn feeder 37, force up the needles located in the same grooves of the needle cylinder into position to take the thread 0 fed by the feeder 37. These jacks thus act as selectors, selecting certain needles, alternate or otherwise, and push them up into position to take thethread from the yarn feeder 37- while the needles in.

the grooves between those having the jacks pass said yarn feeder with hooks below the plane of am taking, and consequently do not taket e thread 6, and thus the straight unsecured thread f shown in the fabric of 'Fig. 19 is produced. .After the elevated needles ii/have taken the thread 6, the cam 35 draws all of them down in theordinary.

manner to form the stitches. It willbe observedthat the edge of the cam ring M is cut out as shown at 39'to permit the needles to gradually engage theedge of the cam ring when drawn down by the cam 11, to prevent injury to the ends of said needles during the rapid revolution of the cylinder. From said diagram 17, itwill be obvious that the needles 1). when elevated above the.

cast off line indicated by the line X'X, will cause the loops contained thereon. and which were formed by the threads supplied from the feeder 38, to pass below the free ends of the latches of said elevated needles onto the shanks thereof and when said needles are drawn down by the cam 35, the loop. referred to will be cast off the needle, retaining thread 6 in the hook thereof.

From the above description it will be obvious that the draw cam 11 when in its extreme inward position, shown in Fig. 7, willengage both .the long and short butts of the needles durin'g the circular knitting. This draw cam will be held in this extreme inward position during the-circular knitting-by the engagement of the upper end '10 of the cam 10, with the spring pulled arm of the bell crank 26-, said cam 10'being held in this position by the engagement of the toe 2 of the lever 3 with the cam of the cam wheel 9, on the camshaft s, as shown in Fig. 1, said toe 2 remaining on said cam Z during the knitting of the leg of the stocking. When the leg has been completed and the mechanism of the machine shifts-to form the heel, Lhe cani wheel 9 will have turned on the shaft 3 sufliciently to cause the toe 2 to drop'into the recess. or

-out out portion 71 of said wheel 9. This dropping of the toe 2 of the lever 3 will cause the band 7 to be shifted sufficiently 'to move the cam 10 laterally under the arm of the bell crank 26 to bring its step '10 under said arm. The spring 30 pulls the arm of said bell crank downward onto said step 10 and moves the rod 12 outward a suiiicient distance to withdraw the cam 11 out of the path of the short 'butt needles, as shown in Fig. 8, said cam 11 being in position then to engage the long butt vate said toe and force said draw stitch of the stocking,

After the cam 11 inward into the position shown in Fig. 7 for engaging the butts of all the needles during the circular knitting forthe formatlon of the foot. This inward move-- ment of the cam 11 is caused by the shifting of the band 7'-to bring the extreme upper end 10 of the cam 10 againunder the spring pulled arm of the bell crank 26. foot has been formed and the mechanism of the machine has been shifted for reciprocatory knitting to form .the' toe the toe 2 ofthe lever 3 will drop into the recess 2 of the wheel 9, thereby moving the band -7 sufficiently to cause the cam'lOto be shifted from under the arm of the bell crank 26 a sufiicient distance to position the step 10 of said'cam under said arm and the spring 30 pulling said arm down onto saidstep causes the rod 12 to be moved outwardly under the action of the bell crank26into the position shown in Fig. 8, for engaging the long butt needles during the reciprocatory action'ofthe cylinder for 'the knitting of the toe ,of the stocking. After the toe of the'stocking hasbeen com pleted and the mechanism of the-machine shifted to form the loo ers hold, the

' cam wheel 9 is turned su ciently to bring the projection I under the toe 2 of the lever 3, whereby the-cam shifting band 7 is moved to bring the upper end 10 of said cam10 under the bell crank arm and thereby forces the rod 12 and the cam 11 at the end thereof inwardly into the position shown in. Fig. 7 for engagement with the butt-s of all the needles during the circular knitting.

After the loopers hplds have been formed and the mechanism of the machine shifted to cause fthestud g of the arm 9 fixed to the vertical sliding bar 9 to move off the end of the cam g and drop into the recess thereof whereby the cam plate H is dropped, as is clearly. described in the Hemphill pat.- ent above referred to, the toe of the lever 2 drops into the recess C of the cam ring 9, whereby the cam shifting band 7 is shifted sufficiently to move the cam 10 out 'of the path of the arm of the bell crank 27, and said arm is drawn down by the spring 30 into-the position shown in Fig. 9, whereby 60 the cam 1.1 is moved outward to its extreme position out of engagement withthebutts of allthe needles. The cam remains in this position until the mechanism of the ma chine is again shifted into position for beginning another stocking, when the toe 2.

willride up onto the cam Z of the wheel 9,

and thereby cause the band 7 to be shifted to bring the upper end 10 of the cam 10 I under the arm of the bell crank 26, whereby the slide 14: is moved inward into the position shownin Fig. 10, thereby compressing the spring 21 and the cam 11 is thusheld under tension in position ready to' be thrown into operation at the will of the operator by moving the gravity pawl 22 upward a sufii- I cient distance to disengage the notch 25 of th'member 24 from theouter end of the bracket 13. It will thus be obvious that this cam '11-may be thrown into operation and used as above described, or it may be held in retracted position as shown in Fig. 10

when it is not'desired for use.

In, the dia amshown in Fig. 18, the knitting of the abric shown in Fig. 20 is performed w thout the use of the cam 11, said cam being disposed out of the way in the position shown in Fig. 10, during this operation. In this diagram, all of the needles which have received the yarn from the feeder 38 receive also the yarn e from the feeder 37,-- certainof said needles being ele vatcd by the jacks 33 in the elevated portion .34 of the cam race'orv track 31, a sufficient distance to cause their latches to pass above the'normal cast off line and thus permit the loops formed by the thread supplied by the feeder 38 to pass onto the shanks of the needles below said latches, and when said needles .are pulled down by the cam 35, the-loop soformed is cast off and thefabric showninFig; 20 produced.

Itwill thus be obvious that the jacks 33 may be employed either inconnection with the cam 11 as shown in Fig. 17, or without it, as shown in Fig. 18, the differences in the fabric produced being shown in Figs. 19 and 20, as above described. I

The cams 35 and36 are fastened to a camblock'similar to the block on which the cams 0'0, 6 e are; mounted and may beoperated either by'hand or automatically to throw them into or 'out of workingposition. When in working position they are placed against the. cylinder" and when not theyearedrawn outwardly a sufiicient distance to escape the butts of the needles.

-To provide for the convenient-insertion and removal of the jacks 33, an opening 40 is formed in the cam ring M and provided with a closure 41 secured in operative position by any suitable means, a -screw being retracting and projecting said cam into and out of the path of the needles, saidmeans vbeing controlled by the shifting of the kniti positioned to lower all of the needles at a. predetermined point into inoperativesposition,'means for automatically retracting said camto position it out of the path-of the;-

short butt needles; selectors for selecting certain of said inoperative needles-and pushing them'into position to takefthe thread carried by said yarn feeder, and to cause the free ends of the'open latches of the elevated needles to pass beyond the normal cast off line, and means for actuating said'selectors when they pass beneath'the yarn feeder.

3. In combination with a grooved needle cylinder having needles slidable in the grooves thereof, a plurality of spaced'yarn feeders for supplying yarn tosaid cylinder, a needle lowering cam arranged between said yarn feeders'in position toengage and lower all of the needles into inoperative position before they reach one of. said yarn feeders to prevent the lowered needles from taking the thread from said last mentioned feeder, selectors for selecting certain of said cam lowered inoperative needles and pushing them up into position to take the thread supplied by said last mentioned yarn feeder, and

means for actuating said selectors when they pass beneath said yarn feeder.

4t. An adjustable needle lowerlng camattachment for knitting machines comprising a U-shaped supporting bracket having apertures in the free ends of its arms and a slot tin-its cross bar, a-rod slid'able in said aperture'd arms and' having a cam fixed to its inner end, a slide mounted on said rod and comprising a bar having laterally extending apertured ends through which said rodpasses, an adjustable member fixed to' said rod between the ends of said slide and having a point depending therefrom and pro "jecting into the slot of said bracket, a coiled spring encircling said rod between'the outer end of said slide and said adjustable memher, a gravity pawl pivotally mounted on the outer endof said rod outside of said U-' trolling said resiliently m hand in presence of shaped bracket and provided on its inner .arm of said bracket to lock the pawl in re tracted position against the tension of the coiled' spring on the rod, and means controlled by the shifting of the knitting mech anism for retracting said rod against the tension of the spring.

'5. An adjustable needle lowerlng cam ta'chmentfor knitting machines comprising .a U-shaped supporting bracket having apertures in the free ends of its arms and a slot vin its cross bar, a rod slidable in said apertured arms and having a" cam fixed to its inner end, a slide mounted on said rod and comprising a bar having laterally extending apertured ends through which 'said rod passes, an adjustablemember fixedtosaid rod-betweenthe ends of said slide and having' a point depending therefrom and projec'ting into the slot of said bracket, a coiled spring encircling said rod between the outer end of said slide and said adjustable mem her, a gravity pawl pivotally mounted on the outerend of said rod outside of'said U- s'haped bracket and provided on its inner .face'with laterally projecting spaced lugs which straddle and are adapted to engage ,the opposite sides of the outer leg of said bracket forlimiting the pivotal movement of said pawl in opposite directions, one of said's'tops having a catch for engaging one arm of said bracket to lock the pawl inv retracted position against the tension of the coiled spring on the rod, a bell crank lever fulcrumed on the inner end of said U-shaped bracket and having one arm thereofpivotally and slidabl'y' connected with the inner .,-end of said slide. resilient means connected with the free end of thefother arm of said bell cranlqand means controlled by the 

